Under heavy power (VTEC engaged, WOT) from 2nd to 3rd I get gridining. Is it likely the synchro going bad; or is it nothing to be really worried about?

My concern is if I go the dealer, they will test drive it, get no grinding because they won't beat on the car, and so they will think I am crazy.

So if I just leave things as are, will the synchro just get progressively worse and thus eventually I can take it in to the dealer when the problem is obvious, or will this cause other damage?

 

From my personal experience, I do believe that this is a common trait to ALL integras (generations 1, 2 and 3). Generally not a big deal unless you are trying to quickly *force* it into gear (which WILL cause the synchros to eventually fail)...

Try and improve on your shifting technique (i.e. waiting for the revs to drop enough, gently grabbing the next gear, etc.) and try not to "beat" on her too much and you should be fine... hth...

 

in the honda civic SI tranny only, there is a service bulletin for the 3 and 5 gear syncros that would cause grinding. if they won't cover it, double clutch